EQUIPMENT PURPOSE, CHARACTERISTICS, CAPABILITIES, AND FEATURES

TM 11-7440-232-12 / NAVELEX 0967-LP-275-5010

c. The MD-701BIUY uses an RFI shielded modem shelf.

d. The MD-701/UY and MD-701A/UY use an unshielded modem shelf.

e. Refer to paragraph 1-10 for the plug-in modules and modem shelf used in each model of the Digital Data

Modem.

f. The location and function of each module are described on the following pages.

· RFI Shielded Modem Shelf Code A 46870 used in MD-701BIUY provides electrically and magnetically shielded

mounting facilities and electrical connections for one complete modem that consists of a power supply and nine plug-in

modules and a module extender.

· The RFI Shielded Modem Shelf is wired for a duplex set consisting of a digital data transmit branch and a digital

data receive branch.

·The RFI Shielded Modem Shelf occupies two mounting spaces on a standard 19-inch equipment rack.

· Code A provides a stable 4.8. MHz crystal clock RF oscillator that mounts in shelf position A9. Position A9 is

equipped with a front retainer plate. This position also has a bracket that holds the oscillator output and ground test

points. The retainer plate contains a center hole, which allows frequency adjustment of the oscillator.

·A termination panel at the rear of the shelf allows external connections to be made by bare or spade-lug terminated

wire or cable. The panel is constructed of a barrier terminal strip, interconnecting cable with connectors, and a metal

housing.

· Modem Shelf*46880 used in MD-701/UY and MD-701A/UY provides unshielded mounting facilities and electrical

connections for one complete modem that consists of a power supply and up to nine plug-in modules and a module

extender. (*Code AB) .

· The modem shelf is wired for a duplex set consisting of a digital data transmit branch and a digital data receive

branch.

· Modem shelf Code A provides a termination panel at the rear of the shelf. This panel allows external connections

(other than ac power and primary protective ground) to be made by bare or spade-lug terminated wire or cable. The

panel is constructed of a barrier terminal strip, interconnecting cable with connectors, and a metal housing.

· Modem Shelf Code B provides a stable 4.8-MHz crystal clock RF oscillator that fits in modem shelf position A9.

Position A9 is equipped with a front retainer plate. This position also has a bracket that holds the oscillator output and

ground test points. The retainer plate contains a center hole, which allows frequency adjustment of the oscillator.

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